The CFAR Flow Cytometry/FACS Core provides state-of-the-art technical and methodologic support and instrumentation in flow cytometric analysis/immunophenotyping and fluorescence activated cell sorting for AIDS investigators at AECOM and collaborating institutions. The FACS Core lab and personnel have nearly a decade of experience in flow cytometric immunophenotype analysis of AIDS patients, and has been a member of the NIAID/DAIDS Flow Cytometry Advisory Committee since 1988. The Core lab has been fully certified in immunophenotype analysis for ACTG specimen processing since the inception of the certification program, and currently serves as the Flow Cytometry lab for seven outside Pediatric ACTG sites in addition to AECOM Adult and Pediatric ACTG specimens. The Core lab also serves as a reference lab for the T-cell determination quality control program of the CDC. The Core lab carries out fluorochrome staining, analysis and sorting on a wide variety of research and clinical specimens, including peripheral blood, semen, bone marrow, mammalian cell lines, and isolated and primary cultures of cells from fetal tissue. In addition, the Core lab and its personnel are involved in collaborative efforts to develop flow cytometric procedures for the evaluation of cellular activation and proliferation, apart from immunophenotype analysis, as well as methodology for concurrent analysis of surface phenotype and intracellular HIV-1 p24. The CFAR Flow Cytometry-FACS Core provides access to quality-controlled analysis of single-dual, and triple-fluorochrome labelled specimens, and the highest quality instrumentation for both analysis and sorting. Because the CFAR Flow/FACS Core is housed within the Institutional P-3 Biohazard Facility, it also provides a unique resource for analysis/sorting of unfixed cells, which can only be carried out in a P-3 environment. The Flow Cytometry/FACS Core has demonstrated ability and capacity for efficiently handling a large and diverse research and clinical specimen load, as reflected in its support of numerous AECOM investigators as well as multiple ACTG sites. In addition, the broad range of experience and expertise of Core personnel in both research and clinical applications of Flow Cytometry. provides an effective foundation for promotion of interactive multidisciplinary collaborations.